4
Table 1. Results of Determination of Amount and Type of Solvent for the Hydrolysis Process
Amount of Solvent ml
Type of Solvent
Acetate Buffer Aquadest
30 DryCaramel
DryCaramel 40
DryCaramel DryCaramel
50 Thick gelatine
Thick gelatine 60
Thick gelatine Thick gelatine
70 Liquid
Liquid
Optimization results showed that the best type of solvent used was aquadest with a weight ratio of substrate weight to solvent of 1 : 5. This conformed to the research conducted by
Wirakartakusumah 1984 which stated that the best startch suspension was the ratio of starch to water of 1:5.
The type and amount of solvent would affect the hydrolysis process, because the gelatine produced at a balanced water to starch ratio would have an ideal consistency and viscosity in the
hydrolysis process. Birch and Parker 1979 stated that good gelatine would facilitate enzyme to break the starch polysacharide chain, because the enzyme used in starch could not attack the
starch granules in intact condition. According to Reed 1975, after expanding the starch granules became more susceptible to chemicals, mechanical force and enzyme work.
5.2. Reducing Agent Sugar Content as a Result of Hydrolysis Process
The Hydrolysis process using sulphuric acid would result in the forming of sugar which for the greater part took the form of the result of simplification of the complex bond found in
cassava peel substrate. Research results indicated that at various concentrations of sulphuric acid used, the highest reducing agent sugar concentration was obtained at a sulphuric acid
concentration of 0.50, that is, 2642 ppm Table 2.
5
Table 2. Reducing Agent Sugar Content at Every Treatment
H
2
SO
4
Concentration Absorbant
Sugar Content ppm
Abs Abs
0.01 0.0208
1607.5 0.25
0.042 0.0208
1757.5 0.50
0.028 0.0208
2642 0.75
0.032 0.0208
2012 0.1
0.02 0.0208
1312
The reducing agent sugar concentration tended to increase in line with increasing concentration of sulphuric acid added. This was due to the fact that the acid broke up starch
molecules randomly, and the break-up produced simpler molecules consecutively until the forming of glucose. The acid first cut off the amorph part in the starch molecule, because it
tended to be more labile with respect to strong acid. When cassava peel four is hydrolyzedwith acid catalyst there will be severing of C-O-C
bond which further will result in glucose and some of tis polymers. When the process is continued, it will increase the sugar proportion with low molecular weight. The polymers were
then hydrolized until they become glucosa Junk and Pancoast, 1977, in Judoamidjojo, 1922. The efficiency of the hydrolysis process could be measured by the Dextrose Equivalent
DE value, in which the DE value was a percentage of the ratio of reduction agent sugar as a result of hydrolysis obtained against the total amount of carbohydrate contained in cassava peel
flour Winarno, 2004. Research results indicated that hydrolysis of cassava peel flour using acid at 0.50
concentration produced the highest DE at 4.80 Table 3. This DE value indicated that not all of the carbohydrate in cassava peel flour could hydrolyzed by the acid.
6
Table 3. The DE value at Every Treatment of Acid Concentration
H
2
SO
4
Concentration Sugar Content
ppm Total Sugar
ppm DE
0.10 1607.5
54840.580 2.93
0.25 1757.5
54840.580 3.20
0.50 2642
54840.580 4.80
0.75 2012
54840.580 3.66
1.00 1312
54840.580 2.39
This conformed to the statement by Judoamidjojo, et al. 1992, that starch conversion using acid would only produce a maximum DE of 55. He also stated that a conversion with a
DE of more than 55 would result in the sugar moleculesrecombining and resulting in a color forming material, also called the Browning effect Judoamidjojo, 1992 and a bitter-tasting
component Winarno, 1983. Further, Howling 1979 in Judoamidjojo et al. 1992 stated that the starch hydrolysis process using acid had only a DE value of 30 - 35.
The hydrolysis process will be more efficient when conducted by using a combined method of acid hydrolysis and enzyme hydrolysis treatment. In this process, the starch was first
hydrolyzed with acid, then hydrolysis was continued with using amylolitic enzyme until it DE reached 61 - 65. This hydrolysis process produced a product which did not a bitter taste and
which did not crystalize quickly Tjokroadikoesoemo, 1986.
5.3. Composition of Lignin, Cellulosa, and Hemicellulosa
